- cape pigweed,
Amaranthus hybridus L.
Amaranthus - derives from the greek word "amarantos" meaning immortal or unfading and "anthos" meaning flower, and refers to long lasting qualities of of the flower; ; hybridus - hybrid.
Amaranthus hybridus is a large erect annual herb, reaching up to 2-3 m, frequently reddish tinted throughout. The stems are longitudinally grooved or ridged, and usually slightly hairy. The leaves are simple and alternate, with a grooved petiole. They are ovate or elliptic-ovate, smooth or slightly undulate along the margins, and pubescent or hairless. The lower side of each leaf has elevated pinnate veins. The petioles are quite long, causing the leaves to droop downward somewhat. The inflorescences are elongated panicle of spikes or simple spikes with small reddish flowers. They are borne at the tip of the stem and in the axils of the leaves. The individual spikes have a bristly appearance because of the linear bracts surrounding the flowers. Small male (staminate) and female (pistillate) flowers are found on the same plant. Each flower has five pink sepals and no petals. The fruit is a one-seeded bladder-like membrane (utricle) that splits apart to release the seed. The small seeds, produced in abundance, are flattened, dark brown or black, circular, and shiny.
Usually much taller than other species oa Amaranthus, but closely related to the ornamental varieties as well as those grown as grain crops in parts of Africa.
Cotyledons 5-8 x 1.5-2 mm, petioles long and slender or the cotyledon base very attenuate.
First pair of true leaves +/- ovate, apex retuse and apiculate, base cuneate or attenuate. At the tenth leaf stage: leaves +/- ovate, apex obtuse, slightly emarginate and aristate, base attenuate. Petioles long and slender. Stem clothed in tortuous pale coloured hairs.
Herb 1-2 (-3) m tall
Taproot, short and stout.
Stems often tinged reddish, erect, occasionally ascending, branched, striate, glabrous to moderately pubescent with multicellular hairs.
Leaves lanceolate to ovate or rhombic, blades 3-19 (-30) cm long, 1.5-8 (-12) cm wide, apex acute to obtuse, with mucron, base cuneate to broadly cuneate, margins entire; lower surface glabrous or sparsely pilose along the margins and veins; lateral veins often pink or red, looping inside the blade margins; petioles 0.5-15 cm long, grooved on the upper surface.
Flowers in yellowish, green, reddish or purple axillary and terminal spikes formed of cymose clusters, which are increasingly closely approximate upwards, the terminal inflorescence varying from a single spike to a broad much-branched panicle up to more or less 45 x 25 cm, the ultimate spike not infrequently nodding; male and female flowers intermixed throughout the spikes.
Flowers yellowish green, reddish, or purple. Each flower subtended by a bract which is longer than the flower. Tepals rather papery, tapering to a fine point at the apex. Male flowers: Flowers about 2 mm long, tepals about 1-1.5 mm long. Anthers about 0.8 mm long. Female flowers: Flowers about 2 mm long. Ovary, styles and stigma about 2 mm long. Ovary laterally compressed, the 'equator' marked by a line. Stigmas three, clothed in glandular hairs.
Utricles obovoid or elongate-ovoid, 1.5-2.5 mm, shorter than tepals, smooth proximally, lid verrucose or rugose, dehiscence regularly circumscissile, or rarely in some presumably hybrid forms, irregularly dehiscent or indehiscent.
Seeds black to dark reddish brown, lenticular to lenticular-globose, 1-1.3 mm, smooth, shiny, faintly reticulate around the margins. Embryo U-shaped, just inside the testa and surrounding or enclosing the endosperm.
Reproduces from its many seeds. The seeds are dispersed by birds. Flowers are wind-pollinated.
Grows in disturbed ground and as a weed of cultivated land.
Native of America.
Weed of crops. Competes strongly for available moisture, light and nutrients.
All species of Amaranthus are susceptible to the normal broadleaf herbicides used in agriculture (with exception of bendioxide) and are easy to remove when small.
|sprinkaanbossie||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|kalkoenslurp||Afrikaans||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|rooibossie||Afrikaans||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|redshank||English||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|isheke||Zulu||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|poea||Sotho||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|umbhido||Zulu||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|hanekam||Afrikaans||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|umfino||Xhosa||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|cape pigweed||English||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|umtyutu||Xhosa||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|misbredie||Afrikaans||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|yhepe||Tswana||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|Pigweed||English||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|yhepe||South Sotho||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|
|umbuya||Zulu||Bromilow C. 2010. Problem plants and alien weeds of South Africa.|